Objectives: To determine whether there is an increase of urinary albumin during and after surgical trauma and investigate a possible relationship between microalbuminuria and the severity of surgical stress.
Design: Prospective study.
Setting: University hospital pediatric intensive care unit.
Patients: Forty consecutive children scheduled for elective surgery.
Interventions: None.
Measurements and main results: Microalbuminuria/urinary creatinine ratio (MACR) was measured before, during, and after elective moderate or major surgical procedures. The Oxford Surgical Stress Score (SSS) was determined for each patient at the end of the operation, and its relationship with maximum deviation of MACR from baseline values was investigated. MACR showed a progressive increase during surgery and a decrease afterward, reaching preoperative values in most cases within 24 hrs after the end of surgery. There was a significant correlation between the increase in MACR and severity of the surgical trauma as measured by SSS. Two patients showed a rise in MACR after the initial postoperative normalization before clinical appearance of a surgical complication and one patient showed a persistent rise in MACR before clinical appearance of a septic complication. None of the other patients showed any rise in MACR after postoperative normalization, and they all had an uneventful recovery.
Conclusions: MACR rises during and after major or moderate elective surgery in children. There is a significant positive correlation between severity of surgical trauma and capillary permeability in pediatric patients. Microalbuminuria, as an index of capillary permeability, may be an early sign of incipient complications and assist in the identification of those patients whose condition will deteriorate. The test is a cheap, blood-sparing, easy-to-perform bedside procedure that may have a useful role in clinical practice for evaluating the effect of surgical trauma on capillary permeability in children.